How to hightlight controls in flowlayoutpanel after click

Question

foreach (Zones zone in result_0)
{
    btn = new UIButton();
    btn.SetDPIScale();
    btn.Text = zone.zoneName;
    btn.Name = btn.Text;
    btn.TagString = zone.Id;
    btn.StyleCustomMode = true;
    btn.Style = UIStyle.Custom;
    btn.Font = new Font("Cambria", 12f);
    btn.Click += BtnZone_Click;

    uiFlowLayoutPanel2.Add(btn);
}

how when i click on button in flowlayoutpanel that button will show that i clicked on it and when i click on another button it will go back to default?

By default the button when added to the flowlayoutpanel it will be blue. I want when I click on some button, it will turn red as a recognition that I have clicked that button. And when I click on another button, the button I just clicked will go back to default blue